var sayIt = function (greeting, name, punctuation) {
  return greeting + ', ' + name + (punctuation || '!');
};

console.log(sayIt('1', '2', '3'));

function partial(fn, str1, str2) {
  return (str3) => {
    return fn(str1, str2, str3)
  };
}

partial(sayIt, 'Hello', 'Ellie')('!!!');
